This same thing happened to me recently on the way to YYZ.

The captain came over the PA to annonce that we had a 150+ knot tailwind with an effective groundspeed of over 700 mph. He also mentioned how unusual it was and that if you looked out the window you could actually see how fast we were going. I wonder if maybe it was the same captain as yours.

We ended up being almost an hour early - which meant sitting on the tarmac for close to 45 mins after landing.